Each document, reference, patent application or patent cited in this text is expressly incorporated herein in their entirety by reference, which means that it should be read and considered by the reader as part of this text. That the document, reference, patent application, or patent cited in this text is not repeated in this text is merely for reasons of conciseness.
The following discussion of the background to the invention is intended to facilitate an understanding of the present invention only. It should be appreciated that the discussion is not an acknowledgement or admission that any of the material referred to was published, known or part of the common general knowledge of the person skilled in the art in any jurisdiction as at the priority date of the invention.
Apparatus, systems and methods have been disclosed for ocular imaging. However, these typically have one or more problems.
In the case of retinal imaging:                corneal reflection and scattering from the internal eye lens may be present in the imaging path, reducing the clarity of images that can be taken;        they inhomogeneously illuminate structures of the eye to be imaged, such as the retina;        they do not provide enhanced fluorescein angiography, autofluorescence and indocyanine green angiography imaging;        internal reflections and/or surface specula reflections from outside the imaging system may be present in the imaging path, producing artefacts in the images taken; and        they do not allow for small pupil illumination or small pupil imaging to be performed, resulting in reduced image quality.        
In the case of slit lamp imaging, the Light Emitting Diode (“LED”) based light sources used typically suffer from a lack of brightness. Such imaging apparatus and systems also typically have poor slit quality and a simplistic construction. In the case of reflex imaging they require the pupil of the eye to be dilated—restricting them to mydriatic reflex imaging for procedures such as imaging the ocular lens for cataract diagnosis and grading.
In the case of non-invasive imaging of the tear film, prior art approaches of using a conical light guide require sophisticated optical engineering to achieve suitable uniform illumination and adequate brightness for satisfactory imaging.
In International Patent Application, Publication No WO 2006/016366 A2 a large and complex retinal imager is described which is not suitable for hand held use or portability. The retinal imager does not support a comprehensive set of imaging techniques to address common eye disease, especially those apparent in the anterior segment of the eye. The retinal imager also does not significantly address problems with coincidence of infrared and white light illumination, resulting in reduced image quality in an infrared preview mode.
International Patent Application, Publication No WO 2005/122874 A1 describes an ophthalmic camera and an ophthalmic camera adaptor which also do not significantly address problems with some of the reflections and coincidence of infrared and white light illumination.
The ophthalmic camera described in International Patent Application, Publication No WO2004/112599 A1 also does not significantly address problems with coincidence of infrared and white light illumination. It also does not support a comprehensive set of imaging techniques to address common eye disease, especially those apparent in the anterior segment of the eye.
The portable slit lamp disclosed in International Patent Application, Publication No WO01/89375 A1 does not support a comprehensive set of imaging techniques to address common eye disease, especially those apparent on the retina of the eye.
Citation or identification of any document in this application is not an admission that such document is available as prior art to the present invention.